Proceedings of the XLVI Italian
Society of Agricultural Genetics - SIGA Annual Congress
Giardini
Naxos, Italy - 18/21 September, 2002
ISBN 88-900622-3-1
Poster
Abstract - 5.14
A TOBACCO MAP KINASE MODULE INVOLVED IN
CYTOKINESIS
CALDERINI
O.*, HEBERLE-BORS E.**, Wilson C.**
*) IRMGPF-CNR, Perugia, Italy
**) Institute of Microbiology and Genetics, University of Vienna, Austria
MAP kinase, cytokinesis,
protein-protein interaction
Numerous plant molecules belonging to a typical MAP kinase
signalling module (MAP kinase, MAP kinase kinase, and MAP kinase kinase kinase)
have been identified. Recent studies have started to link some of these
molecules into a functionally significant interacting partnership. In
particular three tobacco MAP
kinase-pathway members and a kinesin have been involved in a module that
operates during cell division.
In
synchronised cell suspension cultures the activation of the tobacco p43Ntf6
MAP kinase is regulated in a cell cycle-dependent manner, occurring during
anaphase/telophase. The p43Ntf6 protein localises at the
phragmoplast equator (1). Similarly the tobacco MAP kinase kinase kinase NPK1
and the kinesin NACK1also localise at the equatorial zone of the phragmoplast
and expression of dominant-negative mutants of both NPK1and NACK1 results in
defects in cytokinesis (2,3). A novel tobacco MEK, NtMEK1, was identified in a
yeast two-hybrid screen using p43Ntf6 as bait. NtMEK1 is a MAP
kinase kinase that can interact with and activate p43Ntf6 (4).
NtMEK1 is reported to interact with NPK1 (2), therefore a MAP kinase module
composed of NPK1, NtMEK1, and p43Ntf6 might have a role during
cytokinesis in tobacco cells. Characterization of novel members of the pathway
is in progress to further clarify the mechanism of cell plate formation in
plants.
1. Calderini, O., Bögre, L.,
Vicente, O., Binarova, P., Heberle-Bors, E., Wilson, C. (1998) J. Cell Sci.
111, 3091-3100.
2.
Nishihama, R., Ishikawa, M., Araki, S, Soyano, T., Asada, T., Machida, Y.
(2001) Genes Dev. 15, 352-363.
3. Nishihama R, Soyano T,Ishikawa M,Araki S, Tanaka H,
Asada T, Irie K, Ito M, Terada M, Banno H (2002) Cell 109: 87-99.
4. Calderini, O., Glab, N., Bergounioux,
C., Heberle-Bors, E., Wilson C. (2001) J. Biol. Chem. 276, 18139-18145.